CMB2 is very powerful and setting up fields in code prevents accidental changes. get_post_meta() is used on the front end. Neat and fast.
Replacing ACF get_field() with WordPress functions significantly reduced db queries.
I spoke about Child Themes in the inaugural WordCamp Dublin on 14 October 2017. It was a fantastic opportunity. The weekend was perfect for absorbing and sharing knowledge, and everyone was cool and conversations were engaging.
At a WooCommerce talk in WordCamp Dublin I asked about changing a slightly confusing message. Instead of a translation plugin I changed it with code. I feel that it is less confusing now.
Hide custom post types provided by a theme to prevent theme lock-in. Or just to declutter the admin area.
You only need 4 pieces of information to create an Events Manager event in PHP. This is the core of the code I use in a nightly event import script on a client site.